If you load a loop in one Cell which includes slicing information just like a REX file for instance, all of the slices will be mapped over the Cells. If you load a regular audio file on one Cell, it is not possible to slice it automatically. It needs to be done manually, as will be explained below:

Drag the audio file to a Cell.

While holding down the Alt-key you can copy the loop to other Cells

Make sure that every Cell has its own KeyRange: e.g. Cell 1: C1-C1, Cell 2: C#1-C#1, etc. Likewise every cell should be in the same Voice Group (e.g. Voice Group 1) and Max Voices should be set to 1. This can all be done on the Setup tab.

Verify that playback Start Point of Cell 1 is at the beginning of the loop. The end point should be set right after the first beat ends.

Select Cell 2 and move the playback Start Point to the next significant point: e.g. the first snare or HiHat beat, set end point to the end of that beat

Do the same with the other Cells: by moving the Start Point of each Cell to a significant hit of the beat, you can create your own slicing points and since all Cells are in the same Voice Group you will just hear one at a time, e.g. the first Cell's playback stops at triggering Cell 2.

Also every cell should be in the same Voice Group (e.g. Voice Group 1) and Max Voices should be set to 1. This can all be done on the Setup tab.